Ingredients

• 1 tablespoon extra-virgin olive oil

• 1 large shallot, minced

• 1/4 cup red-wine vinegar

• 1/4 cup whole-grain mustard

• 1/4 cup packed dark-brown sugar

• Coarse salt and ground pepper

• 1 side salmon (about 3 pounds), skin removed, cut into 8 fillets

• 1 bunch watercress (about 3/4 pound), thick stems trimmed

• 1 lemon, cut into wedges, for serving

Preparation

  1. STEP 1 Heat broiler, with rack in top position. In a small saucepan, heat oil over medium-high. Add shallot and cook, stirring often until softened, 3 minutes. Add vinegar and cook until slightly evaporated, 1 minute. Add mustard and brown sugar; stir until warm and combined, 1 minute. Season with salt and pepper and remove from heat. (To store, refrigerate cooled glaze in an airtight container, up to 1 day.)
  2. STEP 2 Place salmon fillets on a foil-lined rimmed baking sheet and season with salt and pepper. Transfer 1/2 cup glaze to a small dish and brush on top of salmon. Broil salmon until glaze is bubbling and fish is opaque throughout, 5 to 10 minutes, depending on thickness; brush remaining glaze over fillets. Serve salmon along with watercress and lemon wedges.